Re: [PATCH 2/8] firmware: qcom: scm: Convert SCM to platform driver

Andy Gross
2016-04-23T04:43:56Z

On Fri, Apr 22, 2016 at 04:11:11PM -0700, Bjorn Andersson wrote:
> On Fri 22 Apr 15:17 PDT 2016, Andy Gross wrote:
>
> [..]
> > diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> [..]
> > +static struct qcom_scm *__scm;
> > +
> > +static int qcom_scm_clk_enable(void)
> > +{
> > + int ret;
> > +
> > + ret = clk_prepare_enable(__scm->core_clk);
> > + if (ret)
> > + goto bail;
> > +
> > + if (__scm->iface_clk) {
>
> No need for this check, the clk api accepts NULL.

Ah ok. I wondered about that and then didn't check to see.

> > + ret = clk_prepare_enable(__scm->iface_clk);
> > + if (ret)
> > + goto disable_core;
> > + }
> > +
> > + if (__scm->bus_clk) {
>
> dito
>
> > + ret = clk_prepare_enable(__scm->bus_clk);
> > + if (ret)
> > + goto disable_iface;
> > + }
> > +
> > + return 0;
> > +
> > +disable_iface:
> > + if (__scm->iface_clk)
>
> dito
>
> > + clk_disable_unprepare(__scm->iface_clk);
> > +disable_core:
> > + if (__scm->bus_clk)
>
> and here
>
> > + clk_disable_unprepare(__scm->core_clk);
> > +bail:
> > + return ret;
> > +}
> > +
> > +static void qcom_scm_clk_disable(void)
> > +{
> > + clk_disable_unprepare(__scm->core_clk);
> > + if (__scm->iface_clk)
>
> and here
>
> > + clk_disable_unprepare(__scm->iface_clk);
> > + if (__scm->bus_clk)
>
> and here
>
> > + clk_disable_unprepare(__scm->bus_clk);
> > +}
> > +
> > /**
> > * qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus
> > * @entry: Entry point function for the cpus
> > @@ -72,11 +121,17 @@ EXPORT_SYMBOL(qcom_scm_cpu_power_down);
> > */
> > bool qcom_scm_hdcp_available(void)
> > {
> > - int ret;
> > + int ret = qcom_scm_clk_enable();
> > +
> > + if (ret)
> > + goto clk_err;
>
> Just return here.

right.

>
> >
> > ret = __qcom_scm_is_call_available(QCOM_SCM_SVC_HDCP,
> > - QCOM_SCM_CMD_HDCP);
> > + QCOM_SCM_CMD_HDCP);
> > +
> > + qcom_scm_clk_disable();
> >
> > +clk_err:
> > return (ret > 0) ? true : false;
>
> Unnecessary parenthesis.

will fix that.

>
> > }
> > EXPORT_SYMBOL(qcom_scm_hdcp_available);
> > @@ -91,6 +146,89 @@ EXPORT_SYMBOL(qcom_scm_hdcp_available);
> > */
> > int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
> > {
> > - return __qcom_scm_hdcp_req(req, req_cnt, resp);
> > + int ret = qcom_scm_clk_enable();
> > +
> > + if (ret)
> > + return ret;
> > +
> > + ret = __qcom_scm_hdcp_req(req, req_cnt, resp);
> > + qcom_scm_clk_disable();
> > + return ret;
> > }
> > EXPORT_SYMBOL(qcom_scm_hdcp_req);
> > +
> > +/**
> > + * qcom_scm_is_available() - Checks if SCM is available
> > + */
> > +bool qcom_scm_is_available(void)
> > +{
> > + return !!__scm;
> > +}
> > +EXPORT_SYMBOL(qcom_scm_is_available);
> > +
> > +static int qcom_scm_probe(struct platform_device *pdev)
> > +{
> > + struct qcom_scm *scm;
> > + long rate;
> > + int ret;
> > +
> > + scm = devm_kzalloc(&pdev->dev, sizeof(*scm), GFP_KERNEL);
> > + if (!scm)
> > + return -ENOMEM;
> > +
> > + scm->core_clk = devm_clk_get(&pdev->dev, "core");
> > + if (IS_ERR(scm->core_clk)) {
> > + if (PTR_ERR(scm->core_clk) != -EPROBE_DEFER)
> > + dev_err(&pdev->dev, "failed to acquire core clk\n");
> > + return PTR_ERR(scm->core_clk);
> > + }
> > +
> > + if (of_device_is_compatible(pdev->dev.of_node, "qcom,scm-apq8064")) {
>
> Shouldn't this be reversed?

Right, I inverted this. Will fix.

>
> > + scm->iface_clk = devm_clk_get(&pdev->dev, "iface");
> > + if (IS_ERR(scm->iface_clk)) {
> > + if (PTR_ERR(scm->iface_clk) != -EPROBE_DEFER)
> > + dev_err(&pdev->dev, "failed to acquire iface clk\n");
> > + return PTR_ERR(scm->iface_clk);
> > + }
> > +
> > + scm->bus_clk = devm_clk_get(&pdev->dev, "bus");
> > + if (IS_ERR(scm->bus_clk)) {
> > + if (PTR_ERR(scm->bus_clk) != -EPROBE_DEFER)
> > + dev_err(&pdev->dev, "failed to acquire bus clk\n");
> > + return PTR_ERR(scm->bus_clk);
> > + }
> > + }
> > +
> > + /* vote for max clk rate for highest performance */
> > + rate = clk_round_rate(scm->core_clk, INT_MAX);
> > + ret = clk_set_rate(scm->core_clk, rate);
> > + if (ret)
> > + return ret;
> > +
> > + __scm = scm;
> > + __scm->dev = &pdev->dev;
> > +
> > + return 0;
> > +}
> > +

Thanks for reviewing!